MIPS:[turbofan] Use Nor instruction for bit negation instead of xori.

test/unittests/compiler/mips64/instruction-selector-mips64-unittest.cc

Index: test/unittests/compiler/mips64/instruction-selector-mips64-unittest.cc
diff --git a/test/unittests/compiler/mips64/instruction-selector-mips64-unittest.cc b/test/unittests/compiler/mips64/instruction-selector-mips64-unittest.cc
index 3f31422267287048e9abef3123e9cf795f6d92cd..3d8b6841e1f37240ec957fa6f02013c27076a533 100644
--- a/test/unittests/compiler/mips64/instruction-selector-mips64-unittest.cc
+++ b/test/unittests/compiler/mips64/instruction-selector-mips64-unittest.cc
@@ -400,6 +400,50 @@ INSTANTIATE_TEST_CASE_P(InstructionSelectorTest, InstructionSelectorLogicalTest,
                         ::testing::ValuesIn(kLogicalInstructions));
 
 
+TEST_F(InstructionSelectorTest, Word64XorMinusOneWithParameter) {
+  {
+    StreamBuilder m(this, kMachInt64, kMachInt64);
+    m.Return(m.Word64Xor(m.Parameter(0), m.Int64Constant(-1)));
+    Stream s = m.Build();
+    ASSERT_EQ(1U, s.size());
+    EXPECT_EQ(kMips64Nor, s[0]->arch_opcode());
+    EXPECT_EQ(2U, s[0]->InputCount());
+    EXPECT_EQ(1U, s[0]->OutputCount());
+  }
+  {
+    StreamBuilder m(this, kMachInt64, kMachInt64);
+    m.Return(m.Word64Xor(m.Int64Constant(-1), m.Parameter(0)));
+    Stream s = m.Build();
+    ASSERT_EQ(1U, s.size());
+    EXPECT_EQ(kMips64Nor, s[0]->arch_opcode());
+    EXPECT_EQ(2U, s[0]->InputCount());
+    EXPECT_EQ(1U, s[0]->OutputCount());
+  }
+}
+
+
+TEST_F(InstructionSelectorTest, Word32XorMinusOneWithParameter) {
+  {
+    StreamBuilder m(this, kMachInt32, kMachInt32);
+    m.Return(m.Word32Xor(m.Parameter(0), m.Int32Constant(-1)));
+    Stream s = m.Build();
+    ASSERT_EQ(1U, s.size());
+    EXPECT_EQ(kMips64Nor, s[0]->arch_opcode());
+    EXPECT_EQ(2U, s[0]->InputCount());
+    EXPECT_EQ(1U, s[0]->OutputCount());
+  }
+  {
+    StreamBuilder m(this, kMachInt32, kMachInt32);
+    m.Return(m.Word32Xor(m.Int32Constant(-1), m.Parameter(0)));
+    Stream s = m.Build();
+    ASSERT_EQ(1U, s.size());
+    EXPECT_EQ(kMips64Nor, s[0]->arch_opcode());
+    EXPECT_EQ(2U, s[0]->InputCount());
+    EXPECT_EQ(1U, s[0]->OutputCount());
+  }
+}
+
+
 TEST_F(InstructionSelectorTest, Word64XorMinusOneWithWord64Or) {
   {
     StreamBuilder m(this, kMachInt64, kMachInt64);